Polyamines as short stop agents for azinte color developers



United States atent POLYANHNES AS SHORT STOP AGENTS FOR AZINE COLOR DEVELGPERS Peter Andreyev, Binghamton, N. Y., assignor to General Aniline & Film Corporation, New York, N. Y., a carporation of Delaware No Drawing. Application March 26, 1954 Serial No. 419,095

8 Claims. (Cl. 9655) The present invention relates to an improvement in the processing of light sensitive photographic materials to azine dye images, and more particularly to the use of a short stop bath which is capable of eflfectively removing residual azine developer from said photographic materials.

The processing of light sensitive photographic materials to azine dye images is described in U. S. P. 2,486,440, granted to W. A. Schmidt and V. Tulagin on November 1, 1949, and U. S. P. 2,570,116, granted to R. C. Gunther on October 2, 1951. These patentees recommend, as azine developers, 2,4-diamino auilines, and particularly metanilic acid derivatives, i. e., compounds containing a sulfo group metato one of the substituted amino groups of the 2,4-diamino anilines. Such developers to date have been found to be the most effective in producing the azine dyes. They have, however, a relatively large molecule and for this reason diffuse slowly from photographic emulsions. Furthermore, due to the presence of the sulfonic acid group, the developer and its degradation products tend to be substantive to gelatin. Because of these factors the removal of the developer from the emulsions, either as such or in the form of its degradation products, is difiicu-lt to accomplish. Thus, water washing to remove residual developer is highly impractical because of the time consumption involved.

It is recognized, however, that the residual developer must be removed prior to further chemical treatment, such as bleaching, fixing and the like, since otherwise color development fog would ensue as a consequence of the random oxidation of the residual developer by air or the silver oxidant in the bleaching bath. It was therefore suggested, the art realizing that water washing would not suflice, that short stop baths comprising a pyruvic acid (U. S. P. 2,618,559) or an acid solution of formaldehyde be employed. These solutions are satisfactory for the processing of light sensitive material on a transparent base where a certain amount of stain may be tolerated. However, it was discovered that azine images on white opaque base showed too much stain in the white or high light areas of the image to be acceptable. Neither the pyruvic acid, nor the acid formaldehyde short stop previously proposed, was sufficiently active to prevent the formation of this stain. A serious obstacle was thus pre sented, the aplication of the azine process to latent image development on the one hand, and to white opaque base material on the other hand. The realization of this obstacle has led to strenuous efiorts to find more efiective short stop baths than those previously described.

It has now been discovered, and rather surprisingly so, that the aforesaid stain and color development fog can be completely avoided by subjecting the light sensitive photographic material, after color development and prior to further chemical processing, to the action of a short stop bath comprising an aqueous solution of a polyamine, such as hexamethylenetetramine or its analogue glycosine.

Such short stop baths and their use in the processing of light sensitive photographic materials to azine dye images constitute the purposes and objects of my invention.

My short stop baths are aqueous solutions containing the polyamine in a concentration of about l5%. 'Preferably, the solutions are on the acid side and it has been found that those are most eflective which have a pH from 2 to 3. It is, therefore, recommended that the baths be compounded with a non-oxidizing inorganic or organic acid, such as hydrochloric, sulfuric, phosphoric, citric, acetic, boric or the like in a concentration designed to give a pH below 7. It is to be pointed out, however, that the short stop baths hereof are also efiective in pH ranges as high as 8, and I, therefore, do not desire to limit myself to the use only of acid aqueous solutions of the polyamines.

I have ascertained that the short stop baths are more active when they contain, in addition to the polyamine and acid, a quantity of a clarifying agent, such as glyoxal bisulfite, and use of this reagent, although not essential, leads to better results.

The short stop baths contemplated herein are best compounded as follows:

Polyamine 10-50 parts by Weight Acid suflicient to give pH under 7 Water to make 1000 parts by weight If a clarifying agent be used, it should be present in an amount of from 30 to 50 parts by weight.

The photographic developers utilized in producing the azine dye images are, as previously stated, those described in the aforementioned U. S. Patents 2,486,440 and 2,570,116, and particularly the metanilic acid derivatives described in these patents. Examples of such developers are 4-(13-hydroxyethylamino)-6-phenylaminometanilic acid; 4 (,3 hydroxyethylamino) 6 methylamino metanilic acid; 4 3 hydroxy f3 methyl ethyl amino) -6-phenylamino-metanilic acid and the like.

The azine dyes resulting from the use of such developers are formed through the action of the oxidation products of the developers on color formers of the type described in the aforesaid patents. Preferably, the color formers are located in the emulsion layers and, to this end, they contain a group which renders them non-migratory in the emulsion layers. For practical purposes it is recommended that the photographic material containing the color formers be in the form of anintegral tripack.

The processing of the light sensitive photographic material is substantially the same as described in U. S. P. 2,618,559, excepting that the pyruvic acid short stop solution of the patent is replaced by a short stop bath as described herein. It is to be pointed out that rinsing with oxygenated water following color development and preceding the short stop treatment tends to produce color development fog. It is, therefore, preferable to interpolate the short stop between the color development and bleaching steps. It is possible, however, to incorporate after color development and prior to short stopping a rinse treatment with a strong aqueous solution of sodium bisulfite. This adds an extra step to the processing, however, and hence should be used only where circumstances demand its employment.

The following examples will serve to further illustrate the invention, the parts being by weight unless otherwise stated.

Example I An integral tripack with a bottom layer composed of a red sensitive emulsion containing phenyl-J-acid-N- octadecyl urethane; a middle layer composed of a green sensitive emulsion containing 2-stearoylamine-6-(8-hydroxy-cinchoninoylamino)-toluene-4-sulfonic acid, and a top layer composed of a blue sensitive emulsion containing 2 (4 benzoylacetaminophenyl) l-octadecyl-S-benzimi- Vobtained multicolor stain and tained were completely free 3 dazole sulfonic acid was exposed and the latent image developed in a developer of the following composition:

After color development, the film was rinsed and treated for 5 :minutes'in ta abath' of the following composition:

"Grams aGlyoxal bisulfite 40 Hcxamethylenetetramine Q. 40

V Citric acid; '128 rWatertomakelOOOcc.

The film was washed, bleached in a'ferricyanide' bleach and fixedin'an'acidhardening'solution. Therewere thus fog free "negative dye images. 7

zExample II Three color separationnegativeswere printed onto a film having a white opaque base, but otherwise constituted *as'in Example VI fofU. SQP. 2,570,116; 'The 'film Was then developed in a latent image developer compounded as follows: 7 p l 4-Kfl-hydioxyethylamino) -'6V,-phenylamino metanilic V acid grams 5.8 Add B to A'jus't before using. 1

'lmmediatelyxafter'color development, the filmtwas subjected to tthe'action of a short stop bath having the following constitution:

' Hexamethylenetetramine "grams; 25

Hydrochloric'ac'rd.sutficient to'givejpH 2. 7

Water 'cc 1000 The film'wastthen bleachedin a'ferricyanide bleach and t fixedin an acid hardeninghypo. The dye images obfrom stain and color development fog.

' 7 Example .111

V The "procedure is the'same asin-Example II, excepting equivalent amountof glycosine added to the shortstop bath.

Various modifications of the invention will occur to those skilled in the art and Ltherefore, do not intend to V be limited in the patent grantedexcept as necessitated by the appended claims.

Iclaim:

1. A photographic stop bath efiective to remove residual azine developer'from light sensitivephotographic emulsions comprising an aqueous solution ofa polyamine selected from the class 'consistingof hexamethylenetetramine and glycosine, said solution including glyoxal bisulfite as a clarifying agent, 'and containing suflicient acid to produce a pHbelow 7. 1

2. The stop bath as defined in claim 1, wherein the polyamine is present in a concentration of 1-5% by 7 weight of the solution. V

3. A photographic stop bathefiective to remove residual developer from lightsensitive photographic 'em'ul sions 'comprising'an aqueous solution of 10-50 parts by weightofa po'lyamineselected from the -'class consisting of hexa'methylenetetramine and glycosine, glyoxal bi sulfite as a clarifying agent, 'and sufiicient acid to provide a'pH-of'from'2 to 3. V V p p '4. The composition as defined in'claim 3, wherein" the polyamine is hexamethylenetetramine.

5. -In the process of producing; subtractively colored azine dye images in'a silver halide emulsion layer containing'a colorformer capable of coupling with the oxidaselected from the class consisting of hexamethylenetetrw amine and glycosine and containing sufficient acid to produce a pH below '7, t r

6. The'process as defined in claim 5, wherein the short stop bath contains the polyamine in a concentration of A 1-5 "by weight. 7

7. The process as defined in claim 5, wherein the short stop bath contains 'glyoxal bisulfite as a clarifying agent. 8. The process as-defined in claim 5, wherein the short 0 stop bath'contains per liter of water 40 grams of glyoxal bisulfite, 40 grams of hexamethylenetetramine and suf ficient acid to give a pH 0f from '2 to BL Reierenc-asCited in the file of this patent UNITED "STATES PATENTS 2,618,559 Gunther "Now-18,1952 2,657,139 Bates l octizl, 1953 FOREIGN: PATENTS 7 294,972 'Great'Britain Aug/3, 1928 p OTHER REFERENCES l ChemicalAbstract, 29,4655 (Note 9), 1935. p V Merck Index, publ. byMerck &'Co., Rahway, 'N. 1., fifth ed.,-'1-940, page 353. 

1. A PHOTOGRAPHIC STOP BATH EFFECTIVE TO REMOVE RESIDUAL AZINE DEVELOPER FROM LIGHT SENSITIVE PHOTOGRAPHIC EMULSIONS COMPRISING AN AQUEOUS SOLUTION OF A POLYAMINE SELECTED FROM THE CLASS CONSISTING OF HEXAMETHYLENETETRAMINE AND GLYCOSINE, SAID SOLUTION INCLUDING GLYOXAL BISULFITE AS A CLARIFYING AGENT, AND CONTAINING SUFFICIENT ACID TO PRODUCE A PH BELOW
 7. 